Technique Field
The disclosure relates to a touch sensing device.
Description of the Related Art
The conventional capacitive touch sensing display is formed by externally bonding one or two touch sensing panels to a display panel. The substrate material of the touch sensing panels may be a patterned ITO 0.7 mm or 0.5 mm glass, or a single layer patterned 175 um or 150 um PET/ITO substrate. While the glass substrate is formed at higher temperatures, beneficial for forming low resistance ITO electrode for fabrication of a stacked structure and large area manufacturing, the fabricated glass substrate is not flexible and has low capacitance sensitivity due to the thickness of the glass substrate, hindering applicability. Meanwhile, the PET/ITO substrate is formed at lower temperatures, forming high resistance ITO electrodes, hindering fabrication of a stacked structure and large area manufacturing.
U.S. Pat. No. 7,109,978 discloses a sense plane. The sense plane includes a touch sensor array 22, wherein top, bottom, composite and cross-sectional views are respectively shown in FIG. 1A-1D. The touch sensor array 22 includes a substrate 24 having a first set of conductive traces 26 disposed on a top surface 28 thereof and in a first direction to comprise row positions of the touch sensor array 22. A second set of conductive traces 30 are disposed on a bottom surface 32 thereof and in a second direction orthogonal to the first direction to form the column positions of the touch sensor array 22. The first and second set of conductive traces 26 and 30 alternately contact with the sense pads 34. An insulating layer 36 is disposed over the sense pads 34 on top surface 28 to insulate a human finger or other object therefrom. The substrate disclosed in the U.S. Pat. No. 7,109,978 may be a Print Circuit Board (PCB) or a flexible PCB or any other useable circuit connection structure. The insulating layer 36 is a thin layer (i.e., Mylar). Therefore, in the manufacturing of the sense panel and the display panel, an assembly process for externally bonding is needed.
Thus, it provides a touch sensing device, formed with low resistance ITO electrodes, having high capacitance sensitivity, flexibility and no external bonding assembly process.